From a priest reader:
I had occasion to witness an Ash Wednesday liturgy at [a boy's school] in [___]. As there was no priest planning to be available, the liturgy was conducted by teachers and students. After some readings, the students were invited to extend their hands and to pray a prayer of blessing over the ashes which were then put on the foreheads of the students by other students.
Am I wrong in thinking that there is nothing in Catholic theology to justify a blessing of ashes on Ash Wednesday by a group of laypersons?
No, Father, I do not think you are wrong. Lay people can’t bless in that manner and it was abusive to give them the impression that they could.
I suppose that in the absence of a priest if the students were going to do things with ashes, careful explanations should have been given about what sacramentals are, what priests do, the difference between the priesthood of priests and of the baptized, etc.